diff options
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | kernel/rcutree.c | 13 | ||||
| -rw-r--r-- | kernel/rcutree.h | 2 | ||||
| -rw-r--r-- | kernel/rcutree_plugin.h | 10 |
4 files changed, 17 insertions, 12 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 3fe03151a8e..855fd0d3f17 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1163,6 +1163,8 @@ struct sched_rt_entity { #endif }; +struct rcu_node; + struct task_struct { volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */ void *stack; @@ -1208,7 +1210,7 @@ struct task_struct { #ifdef CONFIG_TREE_PREEMPT_RCU int rcu_read_lock_nesting; char rcu_read_unlock_special; - void *rcu_blocked_node; + struct rcu_node *rcu_blocked_node; struct list_head rcu_node_entry; #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ diff --git a/kernel/rcutree.c b/kernel/rcutree.c index d903e2f2b84..71bc79791cd 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -229,7 +229,6 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) #endif /* #ifdef CONFIG_SMP */ #ifdef CONFIG_NO_HZ -static DEFINE_RATELIMIT_STATE(rcu_rs, 10 * HZ, 5); /** * rcu_enter_nohz - inform RCU that current CPU is entering nohz @@ -249,7 +248,7 @@ void rcu_enter_nohz(void) rdtp = &__get_cpu_var(rcu_dynticks); rdtp->dynticks++; rdtp->dynticks_nesting--; - WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs); + WARN_ON_ONCE(rdtp->dynticks & 0x1); local_irq_restore(flags); } @@ -268,7 +267,7 @@ void rcu_exit_nohz(void) rdtp = &__get_cpu_var(rcu_dynticks); rdtp->dynticks++; rdtp->dynticks_nesting++; - WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs); + WARN_ON_ONCE(!(rdtp->dynticks & 0x1)); local_irq_restore(flags); smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ } @@ -287,7 +286,7 @@ void rcu_nmi_enter(void) if (rdtp->dynticks & 0x1) return; rdtp->dynticks_nmi++; - WARN_ON_RATELIMIT(!(rdtp->dynticks_nmi & 0x1), &rcu_rs); + WARN_ON_ONCE(!(rdtp->dynticks_nmi & 0x1)); smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ } @@ -306,7 +305,7 @@ void rcu_nmi_exit(void) return; smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */ rdtp->dynticks_nmi++; - WARN_ON_RATELIMIT(rdtp->dynticks_nmi & 0x1, &rcu_rs); + WARN_ON_ONCE(rdtp->dynticks_nmi & 0x1); } /** @@ -322,7 +321,7 @@ void rcu_irq_enter(void) if (rdtp->dynticks_nesting++) return; rdtp->dynticks++; - WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs); + WARN_ON_ONCE(!(rdtp->dynticks & 0x1)); smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ } @@ -341,7 +340,7 @@ void rcu_irq_exit(void) return; smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */ rdtp->dynticks++; - WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs); + WARN_ON_ONCE(rdtp->dynticks & 0x1); /* If the interrupt queued a callback, get out of dyntick mode. */ if (__get_cpu_var(rcu_sched_data).nxtlist || diff --git a/kernel/rcutree.h b/kernel/rcutree.h index ca560364d8c..bf8a6f9f134 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -81,6 +81,8 @@ struct rcu_dynticks { struct rcu_node { spinlock_t lock; long gpnum; /* Current grace period for this node. */ + /* This will either be equal to or one */ + /* behind the root rcu_node's gpnum. */ unsigned long qsmask; /* CPUs or groups that need to switch in */ /* order for current grace period to proceed.*/ unsigned long qsmaskinit; diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 04343bee646..47789369ea5 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -92,7 +92,7 @@ static void rcu_preempt_qs(int cpu) rnp = rdp->mynode; spin_lock(&rnp->lock); t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED; - t->rcu_blocked_node = (void *)rnp; + t->rcu_blocked_node = rnp; /* * If this CPU has already checked in, then this task @@ -176,9 +176,9 @@ static void rcu_read_unlock_special(struct task_struct *t) * most one time. So at most two passes through loop. */ for (;;) { - rnp = (struct rcu_node *)t->rcu_blocked_node; + rnp = t->rcu_blocked_node; spin_lock(&rnp->lock); - if (rnp == (struct rcu_node *)t->rcu_blocked_node) + if (rnp == t->rcu_blocked_node) break; spin_unlock(&rnp->lock); } @@ -288,8 +288,10 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, struct rcu_node *rnp_root = rcu_get_root(rsp); struct task_struct *tp; - if (rnp == rnp_root) + if (rnp == rnp_root) { + WARN_ONCE(1, "Last CPU thought to be offlined?"); return; /* Shouldn't happen: at least one CPU online. */ + } /* * Move tasks up to root rcu_node. Rely on the fact that the |